ARMY TM 9-6115-45-24
AIR FORCE TO 35C2-3-444-12
MARINE CORPS TM 09244A/09245A-24/2
NOTE
With the generator running, the voltage will read zero.
b.
Place MASTER SWITCH in OFF position. Connect multimeter leads to terminals 19 and 20 on the governor
control unit (GCU) (A-5), then move the MASTER SWITCH to the START position. Reading should be
battery voltage when the generator does not crank If there is no voltage between terminal positions, the GCU
(A-5) is not functioning properly and should be replaced.
NOTE
With the generator running, there will be battery voltage.
c.
Place MASTER SWITCH in OFF position. Connect multimeter leads to terminals 19 and 18 on the governor
control unit (GCU) (A-5), then move the MASTER SWITCH to the START position. Reading should be zero
voltage when the generator does not crank If there is voltage between terminal positions, the GCU (A-5) is
not functioning properly and should be replaced.
4-3.2
Testing.
a.
Shut down generator set.
b.
Open output box access door. Remove protective cover and attach voltage and frequency recorder to terminals 9
and 12 of voltage reconnection terminal board.
c.
Open load terminal board access door and attach load bank to generator set (4 wire connection).
NOTE
Ensure load bank and generator set voltage reconnections are set for same configuration (i.e.,
120/208 or 240/416 VAC).
d.
Start and operate generator set at rated voltage and frequency.
e.
Turn on voltage and frequency recorder and operate at minimum chart speed of 5 mmnsec (chart resolution of 0.2
sec/mm). Adjust recorder voltage amplifier for a minimum chart resolution of 1.0 volt/mm, and frequency
deviation amplifier for a minimum resolution of 0.2 Hz/mm.
f.
Set load bank for a load equal to 75% of generator set rated load.
g.
Apply and remove the 75% load to the generator set at 40 second intervals three times.
h.
Repeat steps f. and g. at 50% rated load.
i.
Repeat steps f. and g. at 25% rated load.
j.
Repeat steps f. and g. at 100% rated load.
k
Shut down generator set.
I.
Turn off voltage and frequency recorder.
m.
Examine voltage and frequency recorder chart. Generator set should meet the following performance criteria:
(1) Frequency regulation shall not exceed 1/4 of 1 percent of rated frequency.
(2) Frequency short-term stability (30 seconds), frequency will remain constant within a band width equal to 1/2
of 1 percent rated frequency, without repetitive frequency variations, commonly called "hunting".
(3) The generator set will reestablish stable engine operating conditions within 2 seconds of a sudden load
change (within 1 second for 400 Hz unit). The maximum transient frequency change above or below
(overshoot or undershoot) the new steady state frequency shall not be more than 4 percent of rated
frequency (not more than 1-1/2 percent for 400 Hz unit).
n.
If the above criteria is not met, adjust the governor control unit (3, FIGURE 4-3) in accordance with paragraph 4-
3.2.
o.
If the above criteria cannot be met by adjustment, the governor control unit must be replaced.
p.
Disconnect load bank and dose load terminal board access door.
q.
Disconnect voltage and frequency recorder, install voltage reconnection terminal board protective cover and close
output box access door.
Change 2 4-5
